Some musings on the lower than expected transfer of nicotine from e-liquid to bloodstream in comparison to smoking.
While a few do claim to be able to get a similar hit with an e-cig, for many this is not the case; something approaching the same effect only being possible by upping the nic strength beyond what the maths would suggest as equivalent.
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A typical cigarette gives about 1mg nic. This is the absorbed amount determined from testing, not what's in the cigarette.
A typical juice is 20mg/ml with 1ml equivalent to about 10 cigs, perhaps a little less. So potentially 2mg per cig equivalent.
Typical inhale hold would be about 50% exhaled (if hold the vapor for 10 seconds or longer one can retain most of the vapor). So we are about on par now - about 1mg expected to be absorbed.
But the tests show much lower figures, as low as 10%, although we have assumed that the e-cig and e-liquid combination should be an almost perfect delivery mechanism.
So how can this be explained?
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Because the nic in vapor comes dissolved in the base liquid (VG / PG) this will significantly slow down absorption; perhaps the tests didn't sufficiently take this into account. Could be part of the answer, but probably not the whole account.
Perhaps the reasoning that the nic in e-liquid is in an easily absorbable freebase form is not correct. I think unlikely, but possible. Furthermore, amalog smoke only has a freebase content in the 10% - 60% range. So if this part of the answer, the nature of the binding would be very significant; for example, perhaps glycols bind to the active group rendering the nic almost inactive.
Perhaps a fair proportion of the nic gets destroyed in the atomiser due to the fast heat up and nicotine's relatively poor heat stability (it might be a major contributor to heater coil deposit build up). Just my hypothesis at the moment; 50/50 if this really occurs; would be quite a startling discovery if found to be the case.
I can imagine that in the comparative tests that the volunteers did not inhale as deeply with the e-cig as with analogs. However, even allowing for a number of such possibilities bringing the numbers closer, there remains a sizable difference yet to be both adequately explained and proven. It's quite a fascinating area of investigation, and one that might, if that understanding could translate to practical steps to improve the efficiency of the e-cig delivery system, mark a significant step forward.
edit: I am aware that an overlapping issue surrounding the for some people less than equivalent satisfaction may well involve addition co-factors found in analogs, such as MAOIs. Yet distinct from that there is a nic discrepancy that is independent.
While a few do claim to be able to get a similar hit with an e-cig, for many this is not the case; something approaching the same effect only being possible by upping the nic strength beyond what the maths would suggest as equivalent.
~~~
A typical cigarette gives about 1mg nic. This is the absorbed amount determined from testing, not what's in the cigarette.
A typical juice is 20mg/ml with 1ml equivalent to about 10 cigs, perhaps a little less. So potentially 2mg per cig equivalent.
Typical inhale hold would be about 50% exhaled (if hold the vapor for 10 seconds or longer one can retain most of the vapor). So we are about on par now - about 1mg expected to be absorbed.
But the tests show much lower figures, as low as 10%, although we have assumed that the e-cig and e-liquid combination should be an almost perfect delivery mechanism.
So how can this be explained?
~~~
Because the nic in vapor comes dissolved in the base liquid (VG / PG) this will significantly slow down absorption; perhaps the tests didn't sufficiently take this into account. Could be part of the answer, but probably not the whole account.
Perhaps the reasoning that the nic in e-liquid is in an easily absorbable freebase form is not correct. I think unlikely, but possible. Furthermore, amalog smoke only has a freebase content in the 10% - 60% range. So if this part of the answer, the nature of the binding would be very significant; for example, perhaps glycols bind to the active group rendering the nic almost inactive.
Perhaps a fair proportion of the nic gets destroyed in the atomiser due to the fast heat up and nicotine's relatively poor heat stability (it might be a major contributor to heater coil deposit build up). Just my hypothesis at the moment; 50/50 if this really occurs; would be quite a startling discovery if found to be the case.
I can imagine that in the comparative tests that the volunteers did not inhale as deeply with the e-cig as with analogs. However, even allowing for a number of such possibilities bringing the numbers closer, there remains a sizable difference yet to be both adequately explained and proven. It's quite a fascinating area of investigation, and one that might, if that understanding could translate to practical steps to improve the efficiency of the e-cig delivery system, mark a significant step forward.
edit: I am aware that an overlapping issue surrounding the for some people less than equivalent satisfaction may well involve addition co-factors found in analogs, such as MAOIs. Yet distinct from that there is a nic discrepancy that is independent.
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